Tail gas hydrogenation operation

Thread Content

When operating with sulfur exhaust gas, since there were no online ratio meters or online hydrogen analyzers installed on the exhaust gas treatment equipment, we had to determine the air-to-fuel ratio by trial and error; it was set around 1.8. The temperature of the reactor bed ranged from 300 to 340 degrees, the temperature at the reactor inlet was 235 degrees, and the flow rate of acidic gas fluctuated between 1900 and 2200 m/h. The air flow rate was between 3400 and 4000 m/h, while the hydrogen supply was between 160 and 190 m/h. The temperature inside the furnace fluctuated between 1150 and 1170 degrees. The current testing method involves using hydrogen sulfide rapid test strips to measure the hydrogen sulfide levels at the inlet and outlet of the hydrogenation reactor; the hydrogen sulfide level at the inlet is lower than that at the outlet. It is not possible to determine the hydrogen concentration at either the inlet or outlet. The hydrogen sulfide concentration and hydrogen content at the outlet of the exhaust gas tower are measured, while ammonia is added intermittently to keep the pH of the quench water between 7 and 8. The air distribution ratio is obtained by dividing the normal air supply volume by the amount of acidic gas! There’s a contradictory issue here: if I reduce the air supply, the hydrogen sulfide level at the reactor inlet will definitely increase. But the load on the rear tail tower is high (amine concentration of 30, circulation rate of 30 tons/h), and the temperature in the tail furnace will also rise above 800 degrees! In my experience, excessive acid gas levels are a problem; moreover, large fluctuations in acid gas levels make it difficult to maintain stability, and the lack of a ratio meter further complicates control! May I ask if the teacher has any other ways to do this?